Severe impairment of complex I-Driven adenosine triphosphate synthesis in Leber hereditary optic neuropathy cybrids
Severe impairment of complex I-Driven adenosine triphosphate synthesis in Leber hereditary optic neuropathy cybrids
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DOI：
10.1001/archneur.62.5.730
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发表时间：
2005-05-01
影响因子：
--
通讯作者：
Carelli, V
中科院分区：
文献类型：
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作者：
Baracca, A;Solaini, G;Carelli, V
背景资料：Leber遗传性视神经病变（Leber hereditary optic neuropathy，LHON）是一种母系遗传的中枢性视力丧失，与线粒体DNA复合体1（complex 1）的ND亚基的点突变有关。LHON突变的生物化学表型已经使用线粒体胞质杂种（cybrid）进行了研究。细胞模型来源于骨癌亲本细胞系143B.TK-。参与者：从患有LHON的患者中获得成纤维细胞系，如通过存在1种致病性突变所定义的，并从健康志愿者中获得成纤维细胞系作为对照，以构建胞质杂交细胞系。复合物I（顺丁烯二酸）-和复合物11（琥珀酸）依赖的三磷酸腺苷（ATP）的合成，各自的呼吸速率，和总细胞ATP含量进行了研究使用毛地黄皂苷透化胞质细胞。结果：3种LHON突变均使ATP合成和复合物I底物驱动的呼吸控制率降低。相反，琥珀酸驱动的ATP合成，呼吸速率和呼吸控制率不受影响。然而，有缺陷的ATP合成与复合物I底物没有导致ATP细胞内容物减少，表明一个补偿mechanism.Conclusions：LHON致病突变深刻损害复合物I依赖的ATP合成，提供了一个共同的生化特征，可能发挥重要作用，在LHON发病机制。根据突变结果的分层表明，11778/ND 4突变可能诱导胞质杂种呼吸的解偶联，而其他2个突变损害氧消耗速率。
Background: Leber hereditary optic neuropathy (LHON) is a maternally inherited form of central vision loss associated with mitochondrial DNA point mutations that affect the ND subunits of complex 1.Objective: To elucidate the bioenergetic consequences of complex I dysfunction in LHON.Design: The biochemical phenotypes of LHON mutations have been investigated using the transmitochondrial cytoplasmic hybrid (cybrid) cell model derived from the osteocarcoma parental cell line 143B.TK-.Setting: Research laboratories at neuroscience and biochemistry departments at the University of Bologna, Scientific Institute "E. Medea," and University of College Medical School.Participants: Fibroblast cell lines were obtained from patients affected with LHON, as defined by the presence of 1 pathogenic mutation, and from healthy volunteers as controls to construct cybrid cell lines.Main Outcome Measures: Complex I (glutamatemalate)- and complex 11 (succinate)-dependent adenosine triphosphate (ATP) synthesis, their respective respiratory rates, and total cellular ATP content were investigated using digitonin permeabilized cybrid cells. Multiple cybrid cell lines were constructed, introducing, into osteosarcoma-derived rho(0) cells either wild-type or LHON mutant mitochondria carrying each of the 3 common mutations at positions 11778/ND4,3460/NDI, and 14484/ND6.Results: All 3 LHON mutations impaired ATP synthesis and the respiratory control ratio driven by complex I substrates. In contrast, succinate-driven ATP synthesis, respiration rates, and respiratory control ratios were not affected. However, the defective ATP synthesis with complex I substrates did not result in reduced ATP cellular content, indicating a compensatory mechanism.Conclusions: The LHON pathogenic mutations profoundly impair complex I-dependent synthesis of ATP, providing a common biochemical feature that may play a major role in LHON pathogenesis. Stratification of the results by mutation suggests that the 11778/ND4 mutation may induce an uncoupling of cybrid respiration, whereas the other 2 mutations impair the oxygen consumption rate.